1. Field of the Invention
The present invention relates to elevator doors and, more particularly, to an elevator door system having a header track with a door track mounted on the header track via spring clips for guiding elevator doors.
2. Description of the Related Art
Typical elevators have a two-part door for opening and closing the entrance to the elevator cab. The two-part door includes a xe2x80x9cfastxe2x80x9d door portion and a xe2x80x9cslowxe2x80x9d door portion of equal widths. The xe2x80x9cfastxe2x80x9d door portion, located at the leading edge of the two-leaf door, traverses the entire width of the elevator entrance while the xe2x80x9cslowxe2x80x9d door portion traverses only about half the width of the elevator opening. Since the xe2x80x9cfastxe2x80x9d door portion must travel a greater distance, the xe2x80x9cfastxe2x80x9d door is required to move at a speed greater than that of the xe2x80x9cslowxe2x80x9d door so that the xe2x80x9cfastxe2x80x9d door and the xe2x80x9cslowxe2x80x9d door reach the open and closed positions at the same time.
Prior art elevators utilize two separate header tracks: one for guiding the fast door portion and the other for guiding the slow door portion. The slow door header track may be mounted to the entrance of the elevator cab or to the elevator cab itself; the fast door header track, on the other hand, is mounted to the slow door header track. Each header track is a formed metal section having a door track or a rail for providing a running surface for a corresponding door roller.
Manufacture of the header tracks often requires multiple tool setups to complete the forming operations. The punching of holes for fasteners requires special tooling loaded onto machines. Field assembly requires numerous operations: mounting of the slow door header track to the entrance, installation of the door, installation of the fast door header track and adjustment of the header tracks and door tracks to obtain proper door clearance. Retaining devices must also be assembled for each door portion, the header track sections, and the door track sections. In short, the existing design requires more parts, special punching and forming to maintain dimensional tolerances as well as numerous hours of field assembly to properly install the two header tracks.
Furthermore, the door track sections are connected via bolt holes on the header plate. Alignment is not always satisfactory and affects horizontal stiffness, thereby allowing deflection and degrading the door rolling performance.
Accordingly there is a need for an elevator door that requires less manufacturing operations and can be more simply installed.
An object of the present invention is to provide an elevator door that can be manufactured at a lower cost and more readily installed than prior art elevators.
According to an aspect of the invention, a door track for providing a running surface for door rollers is connected to a header track via S-shaped spring clips.
According to another aspect of the invention, a single header track is provided for guiding both the slow and fast door portions. In particular, the header track guides the slow door portion and the leading edge of the fast door portion.
According to another aspect of the invention, the trailing edge of the fast door portion is movably mounted on a rail of a coupling track attached to a hanger panel of the slow door portion. Alignment of the door is accomplished by adjusting the door roller mounted to the trailing edge of the fast door portion and the profile of the rail of the coupling track.
According to still another aspect of the invention, the coupling track on the slow door portion may also be used to support and retain the fast door trailing edge. The slow door hanger panel and the coupling track are held in position by retainers, and the fast door trailing edge is movably supported by the coupling track.
An advantage of the inventive elevator door is that field assembly time is reduced because the fast door portion does not require the mounting of another full-length header track for the fast door portion. Factory assembly of the coupling track to the back of the slow door hanger panel replaces the field work that would have been required to install this other full length track. Field adjustment of the door portions is reduced because of the positional coupling provided by the coupling track and the header track. Time required to replace an elevator door is also reduced because the door portions may be removed without the need to disassemble the header track and the coupling track.
Furthermore, the aluminum extended door track fits securely on the formed metal header and is easily assembled and/or removed therefrom. The spring clips maintain the original installation position. The aluminum material of the door track is a durable surface for a polyurethane roller. Finally, manufacture by the extrusion process provides a higher quality level than a roll formed track or a mechanical brake formed track and header.
In one embodiment, the elevator door system for an entrance opening to an elevator cab includes a two-part door having an open position and a closed position. The two-part door includes a first door portion for traversing across and covering a portion of the entrance opening as the two-part door moves between the open position and the closed position of the two-part door. The two-part door also includes a second door portion for traversing across and covering another portion of the entrance opening as the two-part door moves between the open position and the closed position of the two-part door. A header track includes a rail and a door track mounted on the rail for guiding movement of the first and the second door portions. The first door portion includes a first roller for rolling engagement with the door track so that movement of the first door portion is guided by the door track. An arm extends from a region proximate the leading edge of the first door portion and toward the door track. A second roller, rotatably attached to the arm, is configured for rolling engagement with the door track, so that a leading edge of the second door portion is movably guided by the door track. A coupling mechanism movably couples a trailing edge of the second door portion to the first door portion.
The door track is mounted on the rail of the header track via an S-shaped spring clip having a retaining assembly arranged for retaining the spring clip onto the rail and for retaining the door track onto the spring clip. The retaining assembly includes a first protrusion or barb for engaging an indentation or notch in the header track for retaining the spring clip onto the header track. The retaining assembly also includes a second protrusion for engaging a profile on the door track for holding the door track onto the spring clip. The door track also has a profile to facilitate rolling of the rollers.
Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.